Dantalian no Shoka

Huey inherits his late grandfather's mansion and its vast book collection, along with the responsibility of the "Bibliotheca." Exploring the property, he finds a cellar stacked with books and encounters a girl named Darian, who is reading in silence. Darian wears a large lock in front of her and serves as the gateway to the "Bibliotheca of Dantalian," a place housing the forbidden "Phantom Books."